drm/amdgpu: Add a max ibs per submission limit.

And ensure each ring supports that many submissions. This makes
sure that we don't get surprises after the submission has been
scheduled where the ring allocation actually gets rejected.

My calculations on the existing limits:
COMPUTE v10: 128
COMPUTE v11: 128
COMPUTE v6: 157
COMPUTE v7: 133
COMPUTE v8: 130
COMPUTE v9: 125
GFX v10: 208
GFX v11: 213
GFX v6: 154 (doubling this in the previous patch)
GFX v7: 226
GFX v8: 213
GFX v9: 208
GFX v9 (SW): 208
SDMA CIK: 87
SDMA SI: 97
SDMA v2.4: 74
SDMA v3.0: 74
SDMA v4.0: 72
SDMA v5.0: 51
SDMA v6.0: 52
UVD ENC v6.0: 98
UVD ENC v7.0: 92
UVD v3.1: 124
UVD v4.2: 124
UVD v5.0: 83
UVD v6.0  (VM): 55
UVD v7.0: 51
VCE v2.0: 126
VCE v3.0 (VM): 98
VCE v4.0: 93
VCN DEC v1.0: 49
VCN DEC v2.0: 51
VCN DEC v3.0: 51
VCN ENC v1.0: 58
VCN ENC v2.0: 93
VCN ENC v3.0: 93
VCN ENC v4.0: 93
VCN JPEG v1.0: 17
VCN JPEG v2.0: 16
VCN JPEG v2.5: 17
VCN JPEG v3.0: 17
VCN JPEG v4.0: 17

Link: drm/amd#2498


Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>